As a venerable brand it is hard to look past the Australian Defence Force.

Perhaps Australia’s most revered and nation-defining story – that of Anzac, the centenary of which Australia is about to spend more than $300m on – is constructed on the backs of our men and women who have served in the army, navy and air force.

But the stories we are told of Anzac are all too often the myths – the legends that have grown around fallacies. Such as that our first world war diggers were always wearing the white hats, that they were invariably the knockabout, tough but egalitarian soldiers who had a monopoly on resourcefulness in the trenches and, of course, on that supposedly most Australian of virtues, mateship.

In Australia the tendency – culturally, politically – is to give those who wear our military uniforms, especially at officer rank, the benefit of the doubt.

And so, the story of Anzac has grown around the good. It has left precious little room for the bad or the ugly – of which there was, and still is, plenty.

Which brings us swiftly to the new furore over a plethora of sexual assaults, including among the elite officer trainees of the Australian Defence Force Academy (ADFA), that the ABC’s Four Corners disclosed this week.

The program highlighted the immense difficulty the federal government’s Defence Abuse Response Taskforce (Dart) – established to look into widespread allegations of sexual assault including rape that happened before April 2011 – is encountering in its investigations. Dart was established in response to the DLA Piper external review of sexual assault in defence, which was itself set up after the so-called Skype incident (in which a cadet filmed himself having sex with another and streamed it over the internet to his mates).

DLA Piper was overwhelmed with allegations of abuse going back decades.

Dart has subsequently assessed more than 2,400 abuse complaints and awarded $28m in reparation. It has referred 63 matters to police.

A particular focus of the taskforce is the so-called ADFA 24, a group of cadets who were sexually abused at the Canberra college for officers between 1994 and 1998, and other shocking claims about behaviour at HMAS Leeuwin in Western Australia. Dart was tasked with determining if any of the victims and perpetrators were still serving in the defence force.

Victims had until the end of May 2013 to lodge a complaint with Dart and, therefore, to be eligible for reparation.

But Four Corners found one ADFA 24 victim, Kellie Gunnis, who did not know about the taskforce or the compensation scheme. Several other victims had the same experience.

Meanwhile, alleged perpetrators have been exposed as still serving as officers or elsewhere in defence. Some victims are, shockingly, still in the force alongside them.

The head of the taskforce, Len Roberts-Smith – a former defence force magistrate and WA supreme court Justice – gave an assurance that the taskforce would now remain open to ADFA 24 victims while the defence force chief, General David Hurley, urged victims of sexual assault in the services to come forward.

This is despite the taskforce having access to more than 60,000 defence police records dating back to the 1950s, which the defence force digitised for ease of access in a process called Plan Millennium after the DLA Piper report.

OK, if you’re confused with the investigative processes that are being undertaken by defence and the federal government to get to the bottom of a terrible problem that has been festering in our military institutions – including ADFA and its bases – you are not alone.

Instructively, the defence minister, David Johnston, said he was concerned that sexual assault victims within defence may not be reporting crimes.

“... we can’t unilaterally start to punish people when we don’t have formal allegations,” he said.

Which is, of course, the very crux of this deep institutional scandal that has beset the defence force.

Clearly the investigative processes need to be completely removed from defence, and a wide-ranging, independent, judicial inquiry – such as that which is currently investigating institutional child abuse nationally – is desperately needed.

Such an inquiry needs to actively seek out, reassure and encourage victims to testify. Alleged perpetrators need to be subpoenaed and forced to give evidence.

The federal government and the defence hierarchy must prove they are listening and, once and for all, acting.